1. Field of the Invention
The present invention relates to a measuring apparatus which measures the concentration of a specimen after the specimen to be measured is applied to a test material of a test piece and the test piece is loaded and, in particular, to a measuring apparatus that measures humor of a living body.
2. Description of the Related Art
In a conventional biochemical measuring device, particularly a blood sugar measuring device, after blood to be measured is applied to a test piece and after the lapse of a predetermined time until test paper disposed on the test piece has reacted to the blood, the concentration of the reaction color of the test paper is photoelectrically read out in one measurement. The blood sugar value of the blood is determined on the basis of the concentration value.
At this point, in reading out the reaction color of the test paper, when an analog signal corresponding to the intensity of the light reflected of the light with which the test piece is irradiated is output so that the analog signal is input after it is converted into a digital signal, a corresponding blood sugar value is determined. The A/D conversion and digital input of this analog signal is performed at a predetermined time (for example, after one minute) from the time the blood is applied to the test piece. In the prior art, after a lapse of this predetermined time, only a sampling value of one time is converted into a digital signal and is input.
Digital values which have been converted from analog to digital show discrete step-like values in accordance with the resolution of an A/D converter. Accordingly, the measurement results become discrete step-like values, and thus A/D conversion discrepancies are caused with respect to true analog values. Also, errors caused by intermittently generated noise become large enough not to be ignored when the noises are caused simultaneously at one sampling time.